Apparatus and method for applying spatter finish



I Dec. 26, 1967 Gj w MOD ETAL 3,360,392

Fild July 9, 1964 APPARATUS AND METHOD FOR APPLYING SPAT'I'ER FINISH,

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3,360,392 APPARATUS AND METHOD FOR APPLYING SPATTER FINISH Filed July 9, 1964 Dec. 26, 1967 I w. MOD ETAL 2 Sheets-Sheet 2 Ira e12 ions. GeoryeW 070d- [Z/ward .5 Czyzewjfid j/Zorn Q9.

United States Patent 3,360,392 APPARATUS AND METHOD FOR APPLYING SPATTER FINISH George W. Mod, Mount Prospect, and Edward S. Czyzewski, Northbrook, Ill., assignors, by mesne assignments, to The Celotex Corporation, a corporation of Delaware Filed July 9, 1964, Ser. No. 381,368 7 Claims. (Cl. 117-37) ABSTRACT OF THE DISCLOSURE This invention concerns an apparatus and method for providing a spatter coating on a surface by adjusting the relative speeds of a rotating brush which hurls particles of the coating against a receiving panel and a conveyor carrying the panel past the brush. The method comprises hurling the particles of coating in such fashion that a component of their motion is parallel to but opposite in direction to the direction of movement of the coating receiving panel.

This invention pertains to an apparatus and method for applying a coating to a base material and more particularly to an apparatus and method for applying a coating to a base material to produce a spatter finish.

A spatter finish may be applied to the surface of various panels, tiles or other materials to enhance their appearance. A spatter finish usually gives a knobby or irregular pattern of raised coating materials in the form of droplets on the surface of such materials. In the case of acoustical panels and tiles where a fibrous panel having numerous openings for the reception of sound is used, the use of such a knobby finish is not only attractive but also does not seriously reduce the sound absorption of the panel.

Spatter finishes have been applied by various techniques but with limitations which adversely affect the appearance of the surface or interfere with the efficiency of the manufacture of the process. Thus, a spraying technique has been used to achieve a spatter effect, but clogging of the supply lines and nozzles with the coating material has adversely affected this method. Furthermore, it has been found togbe difficult to achieve an acceptable application of a spatter finish over a large surface.

In the past, coatings have also been applied by means of rotating brushes which fling the coating materials against the surface. However, the droplets of coating materials are not always applied in a satisfactory manner because of what may be termed a-tailing effect. The tailing effect maybe defined as the tendency of the coating materials, as applied, to form with a small tail attached to the large globule. The small tails or streaks of coating materials detract from the appearance of the surface and present difliculties to the sale of spatter finished products. 7

his an object of. the present invention to provide a novel apparatus for applying coating materials to a surface in an efficient manner with a minimum amount of equipment. I

It is another object of the present invention to provide a novel apparatus for applying coating materials to a surface so that the resulting spatter finish is without a tailing effect.

It is yet another object of the present invention to provide a novel method of applying coating materials to a surface to achieve a spatter effect.

Other objects and advantages of the present invention will become apparent to those skilled in the art from a consideration of the specification and drawings in which like numerals indicate like elements and in which:

FIGURE 1 is a perspective view of a part of the apparatus of the invention;

FIGURE 2 is a schematic representation of the elements of the invention in operative relationship; and

FIGURES 3 and 4 are diagramatic representations useful in explaining the invention.

While the following description refers to a preferred embodiment of the invention useful in applying a spatter finish to the surface of an acoustical tile or panel, it will be understood that the particular base material is not to be construed as a limitation of the invention. The spatter finish may be applied to base materials of different types such as but not limited to wood, metal, ceramic, etc. Also, While a spatter paint finish is described, the apparatus and method is also applicable to the deposition of glazes on ceramic tile, flowing paints or cementitious materials such as gypsum, or asphalt.

Referring to the drawings, FIGURES 1 and 2 illustrate the apparatus of the present invention. A conveyor, such as a wide belt 10 is mounted on and stretched between rolls 12 and 13. Roll 13 is driven by means of a motor 15 and a drive chain 17.

The panel 18 to be coated is carried by conveyor belt 10 in the direction shown by the arrow below the paint applicator brush 20. Brush'20 is approximately'as long as the width of the panel 10. Brush 20 is rotated counterclockwise by means of a drive chain 22 and is connected to motor 15 through a speed adjusting gear box 25.

A pair of paint metering rolls 27 and 28 are mounted adjacent each other with a small gap 30 at the nip of the rolls. Metering roll 27 is rotated clockwise by means of a chain drive 32 connecting the shafts of rolls 27 and 28. Metering roll 28 is rotated counterclockwise in facing opposition to roll 27 by means of a chain drive 35 connecting the shafts of metering roll 28 and conveyor roll 13. It is to be understood that mechanical mounting details for the various rolls, the brush and the drive connections may be conventional and per se are not novel. Those skilled in the art can select appropriate chain drives, or other mechanical or electrical drive mechanisms as well as suitable frame mountings and bearings.

The paint receiving surfaces of the metering rolls are preferably formed from rubber and are generally smooth. A paint reservoir 38 having an elongated spout 39 is positioned to feed paint by gravity between metering rolls 27 and 28 so that a puddle of paint 40 is maintained at all times between and above the gap 30 at the nip of rolls 27 and 28.

For reasons which will become more apparent hereinafter brush 20 is placed in close proximity to metering roll 28 so that the ends of bristles 43 are flexed against the surface of roll 28 and the perpendicular distance from the conveyor. belt 10 to the centerline of brush 20 is maintained less than the perpendicular distance from the conveyor belt to the centerline of metering roll 28. The arrows 4'5 illustrate the path taken by the droplets of paint flung by rotating brush 20 toward the upper surface of panel 18.

After the description of the mechanical arrangement of the apparatus of the invention, reference may be had to FIGURES 2, 3 and 4 for an explanation of the operation of the apparatus and an understanding of the method of the invention.

The paint coating which is to be applied to form a spatter finish on the panel 18 is poured into a reservoir 38 and flows by gravity over a spout 39 to form a puddle 40 at the gap 30 of the metering rolls 27 and 28. The conjoint rotation of metering rolls 27 and 28 coats the outer surface of metering roll 28 with a layer of paint. As metering roll 28 continues its counterclockwise rotation, the paint coating is carried to the area at which brush 20 is in contact with the surface of the roll. The bristles 43 of brush 20 which ride up on the surface of roll 28 are flexed upwardly and their tips are immersed in the paint coating on the surface of roll 28. As brush 20 continues to rotate the bristles 43 which have been flexed and bent upwardly are released with a downward whipping action and the paint which clings to the tips of the bristles is thrown upon the upper surface of panel 18 in the form of globules 52 (FIGURE 3).

It has been found that the centerline of the brush 20 must be kept below the centerline of the metering roll 28. T o explain the reason for this condition, reference may be had to FIGURES 3 and 4. FIGURE 4 illustrates the condition where the centerline of brush 20 is horizontally aligned with or is above the centerline of metering roll 28. Arrow 50 illustrates the direction of the path taken by the paint droplets 55 when the centerline of brush 20 is horizontally aligned with or is above the centerline of metering roll 28. It can be seen that the path of the paint droplets 55 is such that it makes an obtuse angle 60 measured counterclockwise from the surface of panel 18 to the path of the paint droplets 55. Under this condition, the droplets 55 which during flight always form with a small tail 56, strike the surface of panel 18 but because the panel is travelling to the right, as indicated by the arrow, the tail 56 of the droplet 55 lies on the surface and is evident when the paint dries. The tear shaped droplet detracts from the appearance of the finished panel 18.

On the other hand, referring to FIGURE 3, arrow 45 illustrates the direction of the path taken by paint droplets 52 when the centerline of the brush 20 is below the centerline of metering roll 28. From another standpoint, the centerline of brush 20 is between the surface of panel 18 and the centerline of metering roll 28. The path of the paint droplets 52 forms an acute angle 61 measured counterclockwise from the surface of panel 18 to the path of paint droplets 52. Under this condition, it can be seen that as paint droplet 52 moves through the air in approaching the surface of panel 18, it has a tail 54. As the paint droplet 52 strikes the surface of panel 18, the tail collapses into the droplet to form a globule without a tail. In this manner, the appearance of the surface of the board is enhanced by the presence of a globule of paint without a tail.

A further consideration of the application of the paint droplets in FIGURES 3 and 4 also reveals that the angle between the path of the droplets and the painted surface of the panel is an acute one. Thus, angle 61 of FIGURE 3 and the complimentary angle to that of angle 60 of FIGURE 4 are both acute and are measured between the painted portion of panel 18 and the path of the droplets, 52 and 55 of FIGURES 3 and 4 respectively.

From a different viewpoint it is evident that a vector component of the direction of movement of the particles is parallel but opposite that of the direction of movement of the panel.

The speed of rotation of metering roll 28 was adjusted so that the linear speed of the surface of the roll was approximately that of the forward speed of panel 18 as it was conveyed under brush 20. This speed relationship is not critical. However, the amount of paint carried by the surface of roll 28 to brush 20 can be adjusted by the speed of the roll. Thus, for a given amount of paint in puddle 40, the greater the speed of rotation of metering roll 28, the greater the amount of paint presented to brush 20 for a given time.

However, the relative speed of rotation of brush 20 and the linear speed of conveyor 10 and panel 18 is critical. In order to insure that the condition shown in FIGURE 3 is maintained, and that tailing is eliminated, it is essential that a speed relationship of between 1 to 1 and 5 to 1 be maintained between the linear surface speed of brush 20 and the linear speed of panel 18. In varying linear speeds of panel 18 from 16 feet per minute to 110 feet per minute, optimum linear surface speeds for brush 20 were 78 feet per minute to 275 feet per minute. The ratio of linear speed of brush 20 to linear speed of panel 18 was from 4.7 to l to 2.5 to 1.

In other experiments for linear speeds of panel 18 between 80 and feet per minute, linear surface speeds of brush 20 were between and 235 feet per minute respectively. A range of relative linear speeds of the brush 20 and panel 18 were between 2.4 to l and 2.1 to 1.

The size of the droplet of paint may be varied by changing the relative speeds of rotation of metering roll 28 and brush 20. As the speed of roll 28 increases, the amount of paint available to the bristles 43 of brush 20 increases and the size of the paint globules increases. Also, as the spacing between the centerlines of roll 28 and brush 20 decreases, the amount of paint picked up by the bristles 43 of brush 20 increases because a greater length of the bristles 43 is immersed in the paint.

Where it is desired to have droplets which retain their shape to present a raised surface, the surface tension of the paint droplets becomes an increasingly important factor. As the surface tension of the paint droplet increases, it will form a globular form. Further, there will be less strike-in of the paint for greater surface tension.

A suitable brush 20 may be 3 inches in diameter with a bristle length of about 1 inch. The bristles are deflected about /2" for optimum whipping action. The filaments are of nylon with a diameter of between 0.011 to 0.012".

The apparatus of the present invention comprises a rotating brush which by flexure of its bristles hurls paint droplets from an adjacent metering roll upon the surface of a moving panel. The relationship between the speed of the brush and the speed of movement of the panel to be coated is critical as well as the relative disposition of the brush, the adjacent metering roll and the panel to be coated.

The method of the invention includes the step of hurling paint droplets toward the surface of a panel along a path which makes an acute angle with the surface of the panel when measured counterclockwise from the said surface.

While a particular embodiment of the invention has been herein shown and described, other modifications, changes and rearrangements will occur to those skilled in the art, and it is intended to cover such modifications, changes and rearrangements in the scope of the appended claims.

We claim:

1. An apparatus for applying a spatter coating finish to the surface of a panel comprising:

an axially rotatable roll far carrying a coating material on its surface;

a conveyor, and means to drive it at a predetermined linear speed, spaced from said roll for conveying a coating receiving panel past said roll at said predetermined linear speed;

an axially rotatable brush having outwardly extending flexible bristles mounted with respect to said roll such that the perpendicular distance from said conveyor to the brush is less than the perpendicular distance from the conveyor to said roll and spaced from said roll a predetermined distance such that some of said bristles are in flexed contact with the surface of said roll; and

means connected to said brush and to said conveyor drive means for rotating said brush at a linear surface speed having a ratio of between 1 to 1 and 5 to 1 with respect to said predetermined linear speed of said conveyor, whereby said flexed bristles of said brush hurl particles of said coating material upon the surface of said panel as said flexed bristles move away from contact with said surface of said roll.

2. An apparatus for applying a spatter coating finish to the surface of a panel comprising:

an axially rotatable roll for carrying a coating material on its surface;

a conveyor, and means to drive it at a predetermined linear speed, spaced from said roll for conveying a coating receiving panel past said roll at said predetermined linear speed;

a brush mounted for rotation adjacent said roll, said brush having bristles which are flexed against the surface of said roll; and

means connected to said brush and said conveyor drive means for rotating said brush at a linear surface speed having a ratio of between 1 to 1 and 5 to 1 with respect to said predetermined linear speed of said conveyor, whereby said flexed bristles of said brush hurl particles of said coating material upon the surface of said panel as said flexed bristles move away from contact with said surface of said roll.

3. An apparatus for applying a spatter finish to the surface of a panel comprising:

a pair of metering rolls spaced from each other to form a gap therebetween;

drive means connected to said metering rolls for rotating said rolls in facing opposition to each other;

means adjacent said pair of metering rolls for depositing a coating material between said rolls at said gap;

a brush mounted for rotation adjacent one of said metering rolls, said brush having bristles which are flexed against said one of said metering rolls;

a conveyor and means to drive it at a predetermined linear speed and mounted below said pair of metering lIOllS said brush for conveying a panel thereunder at said predetermined linear speed; and

means connected to said brush and said conveyor drive means for rotating said brush at a linear surface speed which is in the range of ratios of l to 1 to 5 to 1 with respect to said predetermined linear speed of said conveyor.

4. An apparatus for applying a spatter finish to the surface of a panel comprising:

a pair of axially rotatable metering rolls spaced from each other to form a gap therebetween;

drive means connected to said metering rolls for rotating said rolls in facing opposition to each other;

means adjacent said pair of metering rolls for depositing a coating material between said rolls at said gap;

a conveyor and means to drive it at a predetermined linear speed mounted below said pair of metering rolls for conveying a coating receiving panel thereunder;

an axially rotatable brush having outwardly extending bristles mounted with respect to one of said metering rolls such that the perpendicular distance from said conveyor to the brush is less than the perpendicular distance from the conveyor to said one of said metering rolls and spaced from said one of said metering rolls a distance such that some of said bristles are in flexed contact with the surface of said one of said metering rolls; and

means connected to said brush and said conveyor drive means for rotating said brush at a linear surface speed which is in the range of ratios of l to 1 to 5 to 1 with respect to said predetermined linear speed of said conveyor. 5. An apparatus for applying a spatter finish to the surface of a panel comprising:

a pair of metering rolls spaced from each other to form a gap therebetween;

drive means connected to said metering rolls for rotating said rolls in facing opposition to each other;

a coating reservoir positioned above said rolls for depositing flowable coating material between said rolls at said gap;

a brush mounted for rotation adjacent one of said metering rolls, said brush having outwardly extending flexible bristles and being spaced from said one of said metering rolls a predetermined distance such that at least some of said bristles are in flexed contact with the surface of said one of said rolls;

a conveyor and means to drive it at a predetermined linear speed mounted below said pair of rolls and said brush for conveying a coating receiving panel thereunder at said predetermined linear speed;

and means connected to said brush and said conveyor drive means for rotating said brush at a linear surface speed which is in the range of ratios of 1 to 1 to 5 to 1 with respect to said predetermined linear speed of said conveyor.

6.The method of applying a spatter coating finish to a surface comprising the steps of:

moving said coating receiving surface in a predetermined direction, and

hurling liquid particles of coating material against said surface in a direction such that a component of movement of said particles is in a direction parallel and opposite to said direction of movement of said surface.

7. The method of applying a spatter coating to a panel comprising the steps of:

moving said coating receiving panel in a predetermined direction and at a predetermined linear speed, and

hurling liquid particles of coating material against said surface from a brush rotating at a linear surface speed of between 1 to 1 and 5 to 1 with respect to the me determined linear speed of said panel and in a direction such that a component of movement of said particles is in a direction parallel and opposite to said direction of movement of said surface.

References Cited UNITED STATES PATENTS 220,115 9/1879 Bears 118-300 738,347 9/1903 Myers 117-104X 1,588,062 6/1926 Spivey 239-215 X 1,970,227 8/1934 Frisbie 117-104 X 2,156,901 5/1939 Brady 117- 105.3 2,299,026 10/1942 Merrill 117-1053 2,724,658 11/1955 Lytle 117 104X ALFRED L. LEAVITT, Primary Examiner.

6G I. H. NEWSOME, Assistant Examiner. 

2. AN APPARATUS FOR APPLYING A SPATTER COATING FINISH TO THE SURFACE OF A PANEL COMPRISING: AN AXIALLY ROTABLE ROLL FOR CARRYING A COATING MATERIAL ON ITS SURFACE; A CONVEYOR, AND MEANS TO DRIVE IT AT A PREDETERMINED LINEAR SPEED, SPACED FROM SAID ROLL FOR CONVEYING A COATING RECEIVING PANEL PAST SAID ROLL AT SAID PREDETERMINED LINEAR SPEED; A BRUSH MOUNTED FOR ROTATION ADJACENT SAID ROLL, SAID BRUSH HAVING BRISTLES WHICH ARE FLEXED AGAINST THE SURFACE OF SAID ROLL; AND MEANS CONNECTED TO SAID BRUSH AND SAID CONVEYOR DRIVE MEANS FOR ROTATING SAID BRUSH AT A LINEAR SURFACE SPEED HAVING A RATIO OF BETWEEN 1 TO 1 AND 5 TO 1 WITH RESPECT TO SAID PREDETERMINED LINEAR SPEED OF SAID CONVEYOR, WHEREBY SAID FLEXED BRISTLES OF SAID BRUSH HURL PARTICLES OF SAID COATING MATERIL UPON THE SURFACE OF SAID PANEL AS SAID FLEXED BRISTLES MOVE AWAY FROM CONTACT WITH SAID SURFACE OF SAID ROLL,
 6. THE METHOD OF APPLYING A SPATTER COATING FINISH TO A SURFACE COMPRISING THE STEPS OF: MOVING SAID COATING RECEIVING SURFACE IN A PREDETERMINED DIRECTION, AND HURLING LIQUID PARTICLES OF COATING MATERIAL AGAINST SAID SURFACE IN A DIRECTION SUCH THAT A COMPONENT OF MOVEMENT OF SAID PARTICLES IN A DIRECTION PARALLEL AND OPPOSITE TO SAID DIRECTION OF MOVEMENT OF SAID SURFACE. 